Lecture 16 - Cartilage Flashcards
What are the 3 types of cartilage?
Hyaline Cartilage
Elastic Cartilage
Fibrocartilage
What does the matrix of all cartilage contain?
Proteoglycans
Hyaluronic acid
What cells does all connective tissue contain?
Chondrocytes
What do Chondrocytes of cartilage produce?
Fibres
-Collagen I
-Collage II
-Elastin
What does the matrix of Hyaline cartilage contain?
Collagen II
Proteoglycans
Hyaluronic acid
What does the matrix of Elastic cartilage contain?
Collagen II
ELASTIN
Proteoglycans
Hyaluronic acid
What does the matrix of Fibrocartilage contain?
COLLAGEN I
Proteoglycans
Hyaluronic acid
What cell type is present in Fibrocartilage that is not present in Hyaline Cartilage or Elastic cartilage?
FIBROblasts
What type of cartilage acts as a template for bone production (Endochondral ossification)?
Hyaline Cartilage
In hyaline cartilage, Chondrocytes can be found alone or together in groups, what are these groups called?
Isogenous groups
What are the grooves called which Chondrocytes are found in?
Lacunae
What are the 3 regions found in Hyaline cartilage?
Perichondrial region
Maturing chondral region
Mature chondral region
What is the function of the perichondral region of hyaline cartilage?
Contains stem cells
Differentiate to form chondroblasts
What occurs int he maturing chondral region?
Chondroblasts mature to Chondrocytes
What occurs in the mature chondral region of hyaline cartilage?
Chondrocytes produce Collagen II and maintains the extracellular matrix
What makes cartilage good at shock absorption?
ECM has high water content
Hyaluronic acid helps
What is interstitial growth of cartilage?
Chondrocytes secrete new matrix within the cartilage causing it to grow in LENGTH
What is appositional growth of cartilage?
When Chondrocytes secrete new matrix along existing surfaces causing the cartilage to expand and widen
Where do the Chondrocytes receive nutrients from in hyaline cartilage if its Avascular?
Nutrients from bone can diffuse through the loose extracellular matrix
Where is Hyaline cartilage found?
Trachea
Bronchi
Nose
Articulations surfaces of bones
What type of tissue is perichondrium?
Dense connective tissue
What type of cells line the trachea?
Pseudostratified ciliates columnar epithelial cells
What type of cartilage is the C shaped cartilage reinforcing and holding the airway open?
Hyaline cartilage
What are articulations surfaces?
Joints between bones
In rheumatoid arthritis, what cartilage is attacked?
The hyaline cartilage of the articular surfaces (cartilage of the joints)
What are osteophytes?
When osteocytes form bony spicules on cartilage as a result of cartilage damage
Way to remember where elastic tissue is found?
Where is Elastic tissue found?
The 3 E’s
Epiglottis
Eustachian tube
Ear (pinna)
What is the Eustachian tube?
Tube connecting ear drum to mouth
Role = allows pressure equalisation
What is the Epiglottis?
The flap sitting across the top of the oesophagus which moves to unblock oesophagus when eating
What colour does elastic fibres stain in elastic cartilage?
Intense purple
What 2 types of cell does Fibrocartilage contain?
Chondrocytes
Fibroblasts
How are the cells distributed in Fibrocartilage?
In rows
Where is Fibrocartilage found?
Intervertebral discs
Menisci of knee joint
Pubic symphysis
What are the properties of Fibrocartilage?
Resilient
Shock absorption
Resists shearing forces
What is the function of hyaline cartilage?
Template for bone formation
Smooth surface for articulations
Provides suppport
What is the function of elastic cartilage?
Provides flexibility with elastic recoil
What is the function of Fibrocartilage?
Provides tensile strength
Resists compression
Bears weight
How does Hyalin cartilage appear?
Glossy matrix
Groups of Chondrocytes in lacunae
Invisible collagen II fibres
How does elastic cartilage appear?
Light staining matrix
Dark staining elastic fibres
How does Fibrocartilage appear?
Thick bundles of collagen II
Sparse collage I
Long rows of Chondrocytes in lacunae
In Endochondral ossification what happens to collagen II of hyaline cartilage?
It’s converted to Collagen I
What happens in the zone of proliferation in cartilage at the epiphyseal growth plate?
Cells divide and secrete matrix
What happens in the zone of hypertrophy in cartilage at the epiphyseal growth plate?
Cells enlarge compressing matrix into linear bands
What happens in the zone of calcified cartilage in cartilage at the epiphyseal growth plate?
Enlarged cells degenerate and matrix calcifies forming cartilage spicules
What happens in the zone of resorption in cartilage at the epiphyseal growth plate?
Bone laid down on the cartilage spicules
What is mutated in Achondroplasia?
FGFR3 gene
What does FGF (Fibroblast Growth Factor) promote?
Collagen formation from cartilage
What is affected in Achondroplasia?
Endochondral ossification
What dos Achondrooplasia cause in an individual?
Short stature (normal sized head and torso)
What are the 2 types of arthritis?
Osteoarthritis
Rheumatoid arthritis
What is Osteoarthritis?
Age related degeneration of articular cartilage
Joint space narrows
Bone rubs against bone
How is pain caused in Osteoarthritis?
Growth of bony spurs occurs (osteophytes)
Causes pain and inflammation
What type of disease is Rheumatoid arthritis?
Autoimmune disease
What is attacked in Rheumatoid arthritis?
Auto antibodies attack synovial membrane
Synovial cells become inflammed
Inflammed synovial cells proliferate forming a pannus
Pannus degenerates cartilage and bone at joint causing deformity
How does Rheumatoid arthritis cause pain/
Synovial membrane gets inflammed thickening the joint capsule
Damages bone and cartilage causing osteophytes to be made